Unmanned helicopter

ABSTRACT

The invention relates to an unmanned helicopter comprising an internal combustion engine and an associated fuel tank. The unit ( 1 ) formed by the internal combustion engine and the gearbox is arranged essentially in a self-supporting housing ( 2 ) which is at least partially closed all the way round, and preferably consists of carbon fiber-reinforced plastic (CFK), a nose body ( 3 ) being connected to the front of said housing. In this way, a compact structure can be achieved.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of PCT applicationPCT/AT2005/000183, filed 27 May 2005, published 19 Jan. 2006 asWO2006/005087, and claiming the priority of Austrian patent applicationA1202/2004 itself filed 15 Jul. 2004, whose entire disclosures areherewith incorporated by reference.

FIELD OF THE INVENTION

The invention pertains to an unmanned helicopter with an internalcombustion engine and a dedicated fuel tank.

BACKGROUND OF THE INVENTION

Unmanned aircraft are frequently used for reconnaissance flights overhazardous areas. These unmanned aircraft are radio-controlled.Helicopters are particularly practical for taking reconnaissancephotographs because they are able to hover in a practically stationaryposition and have vertical take-off and vertical landing capabilities.

Conventional unmanned helicopters comprise a main body that accommodatesthe internal combustion engine and essentially consists of a coveredthree-dimensional framework. The manufacture of such a design isrelatively costly and also results in a heavy construction that mayreduce the maximum payload.

OBJECT OF THE INVENTION

The invention is based on the objective of developing an unmannedhelicopter that can be easily manufactured and has a compact design.

SUMMARY OF THE INVENTION

This is achieved in that the unit consisting of the internal combustionengine and the transmission is arranged in a self-supporting housingthat is at least partially closed on all sides and preferably consistsof carbon fiber-reinforced plastic (CFK), with a nose body beingconnected to the front of the housing.

In addition to the compact design of the unmanned helicopter accordingto the invention, the housing for accommodating the unit consisting ofthe internal combustion engine and the transmission may also be realizedin an at least partially hollow fashion and used as fuel tank. In thisembodiment, it is not necessary to manufacture a separate fuel tank andto install this separate fuel tank with consideration of the position ofequilibrium of the helicopter.

In one practical embodiment of the invention, the exhaust of theinternal combustion engine is arranged in a recess of the housing thataccommodates the unit consisting of the internal combustion engine andthe transmission, wherein the recess is open toward the outside and canbe closed with a cover.

In order to optimize the cooling of the internal combustion engine, aradiator of the internal combustion engine is arranged on the upper sideof the nose body and a coolant flows through the radiator. Consequently,the radiator is directly subjected to the air accelerated by thehelicopter rotors such that the cooling effect is optimized.

An oil cooler is advantageously arranged underneath the radiator of theinternal combustion engine. This means that the cooling air arrivingfrom the rotors is utilized twice.

The exhaust is cooled in order to remain inconspicuous to thermalimaging cameras. This is realized by surrounding the exhaust of theinternal combustion engine with a double casing, wherein the cooling airarriving from the radiator flows through the outer annular space and thecooling air arriving from the rotor bearing of the internal combustionengine flows through the adjacent inner annular space.

The invention is described in greater detail below with reference to oneembodiment that is illustrated in the figures. However, the invention isnot limited to this particular embodiment.

BRIEF DESCRIPTION OF THE DRAWING

The figures show:

FIG. 1, a schematic representation of a helicopter according to theinvention;

FIG. 2, a schematic representation of the housing for accommodating theinternal combustion engine and of the nose body, wherein thisillustration is enlarged in comparison with FIG. 1;

FIG. 3, a section through the housing provided with the fuel tank, and

FIG. 4, a section through the exhaust.

SPECIFIC DESCRIPTION

The figures show that a helicopter according to the invention comprisesa housing 2 that essentially accommodates the unit 1 consisting of theinternal combustion engine and the transmission, wherein a nose body 3is connected to the housing 2 and the unit 1 protrudes into this housing2. A tail section 4 is connected to the rear of the housing 2. Theinternal combustion engine of the unit 1 is realized in the form of arotary engine that drives a main rotor 5 and a tail rotor 6.

The housing 2 for accommodating the unit 1 is realized in a hollowfashion, and the hollow space serves as a fuel tank 7 that is providedwith a fuel line 8. A recess 10 of the housing 2 is open toward theoutside and accommodates the exhaust 9, the design of which is discussedbelow with reference to FIG. 4. A through-opening 11 is provided for theshaft of the main rotor 5.

A radiator 12 of the internal combustion engine is arranged on the upperside of the nose body 3, and a coolant flows through this radiator. Theradiator 12 is subjected to the air current generated by the main rotor5 such that the cooling effect is optimized. The air emerging from theradiator 12 subsequently flows through an oil cooler 13.

The exhaust 9 is cooled in order to remain inconspicuous to thermalimaging cameras. According to FIG. 4, the conical exhaust pipe 14 issurrounded by a double casing. The cooling air arriving from theradiator 12 flows through the outer annular space 15, and the coolingair arriving from the rotor bearing of the internal combustion engineflows through the inner annular space 16. This makes it possible tolargely isolate the exhaust gas flowing through the exhaust pipe 14. Inaddition, the recess 10 containing the exhaust 9 is closed with a cover17.

The scope of the invention allows various modifications. For example,the cooling could be realized in a different way. It would also bepossible to arrange the exhaust at a different location, etc.

1. An unmanned helicopter comprising: a self-supporting housing closedon all sides and formed of carbon-reinforced plastic; a central unitinside the housing and holding an internal-combustion engine and atransmission inside the hollow unit, the unit forming with the housing aspace surrounding the unit and adapted to hold fuel; and a helicopternose body connected to and projecting forwardly from the housing, theengine and transmission projecting into the nose body.
 2. The unmannedhelicopter according to claim 1 wherein exhaust of the internalcombustion engine is arranged in a recess of the housing, the recessbeing open toward the outside and closable with a cover.
 3. The unmannedhelicopter according to claim 1 wherein a radiator of the internalcombustion engine is arranged on the upper side of the nose body and acoolant flows through this radiator.
 4. The unmanned helicopteraccording to claim 3 wherein an oil cooler is arranged underneath theradiator of the internal combustion engine.
 5. The unmanned helicopteraccording to claim 1 wherein exhaust of the internal combustion engineis surrounded by a double casing, wherein the cooling air arriving fromthe radiator flows through the outer annular space and the cooling airarriving from the internal combustion engine flows through the adjacentinner annular space of the double casing.